Fix import_sec_context with interposers

The code was correctly selecting the mechanism to execute, but it was
improperly setting the mechanism type of the internal context when the
selected mechanism was that of an interposer and vice versa.

When an interposer is involved the internal context is that of the
interposer, so the mechanism type of the context needs to be the
interposer oid.  Conversely, when an interposer re-enters gssapi and
presents a token with a special oid, the mechanism called is the real
mechanism, and the context returned is a real mechanism context.  In
this case the mechanism type of the context needs to be that of the
real mechanism.

ticket: 7592
target_version: 1.11.2
tags: pullup

1 files changed, 14 insertions, 21 deletions

diff --git a/src/lib/gssapi/mechglue/g_imp_sec_context.c b/src/lib/gssapi/mechglue/g_imp_sec_context.c
index 53310ddcea..a0e2d71221 100644
--- a/src/lib/gssapi/mechglue/g_imp_sec_context.c
+++ b/src/lib/gssapi/mechglue/g_imp_sec_context.c
@@ -84,6 +84,7 @@ gss_ctx_id_t *		context_handle;
     gss_union_ctx_id_t	ctx;
     gss_ctx_id_t	mctx;
     gss_buffer_desc	token;
+    gss_OID_desc	token_mech;
     gss_OID		selected_mech = GSS_C_NO_OID;
     gss_OID		public_mech;
     gss_mechanism	mech;
@@ -100,12 +101,6 @@ gss_ctx_id_t *		context_handle;
     if (!ctx)
 	return (GSS_S_FAILURE);
 
-    ctx->mech_type = (gss_OID) malloc(sizeof(gss_OID_desc));
-    if (!ctx->mech_type) {
-	free(ctx);
-	return (GSS_S_FAILURE);
-    }
-
     if (interprocess_token->length >= sizeof (OM_uint32)) {
 	p = interprocess_token->value;
 	length = (OM_uint32)*p++;
@@ -120,12 +115,9 @@ gss_ctx_id_t *		context_handle;
 	return (GSS_S_CALL_BAD_STRUCTURE | GSS_S_DEFECTIVE_TOKEN);
     }
 
-    ctx->mech_type->length = length;
-    ctx->mech_type->elements = malloc(length);
-    if (!ctx->mech_type->elements) {
-	goto error_out;
-    }
-    memcpy(ctx->mech_type->elements, p, length);
+    token_mech.length = length;
+    token_mech.elements = p;
+
     p += length;
 
     token.length = interprocess_token->length - sizeof (OM_uint32) - length;
@@ -136,7 +128,7 @@ gss_ctx_id_t *		context_handle;
      * call it.
      */
 
-    status = gssint_select_mech_type(minor_status, ctx->mech_type,
+    status = gssint_select_mech_type(minor_status, &token_mech,
 				     &selected_mech);
     if (status != GSS_S_COMPLETE)
 	goto error_out;
@@ -152,6 +144,12 @@ gss_ctx_id_t *		context_handle;
 	goto error_out;
     }
 
+    if (generic_gss_copy_oid(minor_status, selected_mech,
+			     &ctx->mech_type) != GSS_S_COMPLETE) {
+	status = GSS_S_FAILURE;
+	goto error_out;
+    }
+
     if (mech->gssspi_import_sec_context_by_mech) {
 	public_mech = gssint_get_public_oid(selected_mech);
 	status = mech->gssspi_import_sec_context_by_mech(minor_status,
@@ -167,16 +165,11 @@ gss_ctx_id_t *		context_handle;
 	return (GSS_S_COMPLETE);
     }
     map_error(minor_status, mech);
+    free(ctx->mech_type->elements);
+    free(ctx->mech_type);
 
 error_out:
-    if (ctx) {
-	if (ctx->mech_type) {
-	    if (ctx->mech_type->elements)
-		free(ctx->mech_type->elements);
-	    free(ctx->mech_type);
-	}
-	free(ctx);
-    }
+    free(ctx);
     return status;
 }
 #endif /* LEAN_CLIENT */